1. Scope of the Invention
The invention concerns a protective cover intended to be mounted on the rear bearing of a polyphased rotating electrical machine, particularly an alternator or alternator-stator for an automobile vehicle.
2. State of the Technology
Rotating electrical machines of the type that consist of an outer frame equipped with a front bearing and a rear bearing, a rotating rotor shaft mounted in the front and rear bearings of the frame, a rotor supported by said shaft and equipped with a field coil connected by electrical links to two slip rings carried by the rear end of the shaft, a coiled stator surrounding the rotor and equipped with several phases, the outlets of which are connected to a phase connector for connection to an exterior electronic module, a phase connector support of an electrically insulating material, fixed-mounted on the rear bearing and a cover that is fixed-mounted on the rear bearing, which covers at least one brush holder, the brushes of which are intended to act as supports on slip rings integrated with the rear end of the rotor shaft and connected to at least one field coil comprising the rotor.
In this machine, the cover covers the support of the phase connector, which is one piece with a brush-holder, which houses brushes up against said slip rings and with one brush-holder connector for linking the brushes to the electronic module containing an alternating current rectifying device of the coiled stator.
Such a machine is described in document WO 01/69762.
FIG. 1, which reproduces FIG. 1 of this document, but eliminates the references to parts and components that are not necessary for an understanding of the invention, shows a protective cover 17, which covers the rear bearing 14 and, with the bearing, the brush-holder referenced 16, the brushes of which are shown in the application against the slip rings 6, 7 connected by wire links to the field coil as explained in document WO 01/69762.
The cover is attached to the rear bearing. The brushes are connected electrically to a voltage regulator mounted on the outside of the machine. In this case, the voltage regulator belongs to the electronic module, which is an electronic command and control module. More specifically, as the rotating electrical machine is an alternator-starter in this case, this electronic module is comprised of a power module that includes the rectifier device, and a module for control and interface with the onboard network of the vehicle and/or with the control module of the vehicle's internal combustion engine. This control module manages the power functions in alternator and starter modes, regulation in alternator mode, and the transition from starter mode to alternator mode. As a variant, when the machine is an alternator, the electronic module is simplified, since the control module does not have to manage the transition function from starter mode to alternator mode; the machine runs only in alternator mode. The rectifier device of the power module may, in this case, have only diodes.
FIG. 1 also show at 3 the shaft of the machine, at 4 the rotor with clamps integrated in rotation with the shaft 3 and holding the field coil between its two polar wheels, the stator at 8, the front bearing at 13, and the rear and front fans at 42 and 43 which are integrated in rotation with the rotor 4.
In a variant, the rotor has projecting poles and is comprised of several field coils, as described for example in document WO 02/054566, and as mentioned in the aforementioned document WO 01/69762. The machine in a variant is cooled by fluid circulation; at least one of the two bearings 13, 14 is hollow for fluid circulation, such as the cooling fluid of the thermal motor of the vehicle. The presence of the fans is not, therefore, required. In a variant, only the rear fan is present.
This machine presents an axial axis of symmetry (not referenced in FIG. 1), which is merged with the axis of the shaft 3, and which defines the axis of rotation of the rotor and the radial and axial directions of the machine. The front 13 and rear 14 bearings are connected together, by rods, one of which is visible in FIG. 1, to form an outer frame intended to be mounted on a fixed part of the automobile vehicle. This frame serves as the housing and support for the stator 8 and the rotor 4.
For this purpose, the frame carries the stator 8 fixed on its outside periphery and the shaft 3 centrally in rotation. To do this, the bearings 13 and 14 each carry centrally a ball bearing for rotating mounting of the shaft 3, the front end of which carries a pulley intended to be connected through a belt transmission device to the internal combustion engine of the automobile vehicle, while the rear end of the shaft 3 carries the rings 6,7.
The bearings 13, 14 present on the external periphery an annular skirt with an axial orientation, and each presents, inside, at the free end, a change in diameter to axially lock and center the body presented by the stator 8 inserted between the free ends of the skirt of the bearings 13, 14.
Thus, this stator 8 has a grooved body, traditionally formed by a packet of sheets, supporting field coils crossing the body of the stator along the grooves of the stator to extend in an axial projection on either side of this body in order to define a front chignon and a rear chignon partially surrounding the front fan 43 and the rear fan 42 respectively to be cooled by the fans. The number of field coils depends on the number of phases of the electrical machine. Coils are made in the known manner by winding an electrical wire or bars in the grooves of the body of the stator, shaped for example in a U, in which the ends of the branches are connected by welding to form the winding.
In a known manner, the rear chignon is comprised of outlets, known as phase outlets, that cross the rear bearing to the openings of the bearing, as shown (for one of them for example) in the lower part of FIG. 1a of document EP A 210090, to be connected as described below to a phase connector via phase connection inputs and electrical tracks.
The machine shown is an alternator-starter comprised of means to track the rotation of the rotor 4. These means are magnetic and have a radial read reluctor 50, which is carried by a reluctor-holder part, which is known but not shown, and sensors 52 carried by a sensor holder indicated at 53. This sensor holder 53 has at least one protuberance crossing an opening of the rear bearing 14 for installation of the sensors 52 opposite the reluctor 50 and the reluctor radial reader. This sensor holder is supported by the rear bearing 14 and is in contact with the rear surface of the bearing 14. As shown in FIG. 2, the sensor holder 53 has two wings with oblong openings (not referenced) for angle adjustment; it is locked using washers and nuts screwed on studs mounted in the rear bearing 14, one of which can be seen in FIG. 1, which cross the oblong openings. The sensor holder 53 is mounted and screwed between the bearing 14 and the washers supporting the nuts.
In the protective and phase support device, containing the cover 17 and the phase support according to document WO 01/69762, the brush holder and the sensor holder each have a connector to connect respectively the brushes and the sensors to the electronic command and control module installed on the outside of the machine and, more specifically, to the voltage regulator, which drives the field coil of the rotor 4, and to the device rectifying the alternating current produced by the coiled stator of the alternator-starter when it operates in generator mode; this voltage regulator device is part of the electronic module as cited above.
Thus, we see at 257 the connector of the sensors 52 supported by the sensor holder 53 and, at 162, the connector of the brush holder 16. Electrically conducting tracks sunk in the sensor holder 52 made of electrically insulating material connect the connector 257 to the sensors 52. As FIG. 8 of this document shows, the connector 162 of the brush holder 16 is mounted on a support designated with the reference 160, made of an electrically insulating material, which is in the general form of a disk and is mounted on the rear bearing 14 with two studs. FIG. 2 attached reproduces this FIG. 8.
On this figure, we see on the periphery of the support three connection inputs for the phases designated by the references 163, 164 and 165, each intended to receive a mounted phase output of the windings of the stator (triphased here). These inputs are connected by electrically conducting tracks, which are sunk in the support 160, to the first electrical contact faces 166 to 168. The faces 166 to 168 are placed on an extension of the support 160 and are part of a first connection sub-assembly 161, called the phase connector for reasons of simplicity, so that a device for electrical connection of the stator phases is formed comprised of the phase connector, the electrically conducting tracks, and the phase connection inputs.
A second sub-assembly with additional electrical contact faces, male in this case, is intended to be mounted on the connector 161, female in this case, to form a first connector that connects the phases of the stator to the exterior command and control module via electrical cables, and a second connector, the same type as the first connector, comprising a second phase connector partially carried by the electronic module. The first connector-cables-second connector assembly constitutes an electrical connection device between the machine and the electronic module.
The first connector is described in greater detail in document FR 2 819 943. We will refer for more details to the two documents from the known technology just cited.
In the protective and support device of the phase connector of the rotating electrical machine, which is known, the second sub-assembly of the first phase connector splits axially into the extension of the support 160 and the cables that go to the electric module are oriented in the radial direction of the machine, at the output of the second sub-assembly, the position of which is imposed by the extension of support 160. This extension is close to the brush holder 16.
Now, in certain applications, it would be preferable to remove the cables differently, for example for issues of size related to the presence of parts or walls adjacent to the machine.